Method of making an intra-ocular lens-mount element

ABSTRACT

The invention contemplates improved techniques for making lens implants for use in ophthalmological surgery, the lens being a replacement for a cataract-clouded natural lens, and the replacement being installed in the pupil at the iris as the operative step following removal of the cataracted lens. The lens produced by the inventive method features adapter structure assembled to an intra-ocular lens element and having first and second pluralities of radially outward stabilizing feet, in angularly spaced and interlaced relation with the feet of the other plurality; and the respective pluralities of stabilizing feet are on opposite sides of the iris, thus enabling the iris to retain and position the implanted lens.

This application is a continuation of my copending application Ser. No.858,373, filed Dec. 7, 1977, now abandoned, and said copendingapplication is a division of my continuation-in-part application Ser.No. 780,682, filed Mar. 23, 1977 (now U.S. Pat. No. 4,080,709), which inturn is a continuation-in-part of my original application Ser. No.691,033, filed May 28, 1976 (now U.S. Pat. No. 4,073,014).

The invention relates to methods of making an improved lens implant, asa replacement for a cataract-clouded or otherwise diseased natural lens.

As many as 500,000 Americans a year require surgery for removal of anatural lens which has become opaque (cataract), causing loss of vision.The modern therapy for cataract is surgical removal; this is generallydone either by gently lifting the opaque lens from the eye in one piece,or by fragmenting the lens and washing out the fragments. When thecataractous lens is removed, an alternate method must be provided tofocus light entering the eye, so that a sharp image focuses at theretina. Strong spectacle lenses and contact lenses are both commonlyused for this purpose, but both have important shortcomings. Strongspectacle lenses tremendously enlarge the image, foreshorten distances,restrict peripheral vision, and prevent both eyes from being usedsimultaneously if both eyes have not had cataract surgery; contactlenses overcome some of these problems but introduce others, involved ininsertion, removal and frequent maintenance.

The concept of implanting an intra-ocular lens in place of the removednatural lens is not new, although it is of relatively recent origin. Todate, however, a significant limitation on such a procedure has been therelative unavailability of implant lenses, for their production hasrelied upon small, craft-style workshops, and lens quality has been lessthan satisfactory.

It is accordingly an object of the invention to provide an improvedmethod for making intra-ocular lenses, for implant procedures of thecharacter indicated.

Another object is to provide a method for making improved mountingstructure for such lenses, whereby operative procedures may be moresafely and reliably performed.

It is also an object to provide a method for making such lenses completewith mounting structure, of inherent high quality, adherence tospecifications, and reproducibility by precision mass-productiontechniques.

Other objects and various further features of novelty and invention willbe pointed out or will occur to those skilled in the art from a readingof the following specification, in conjunction with the accompanyingdrawings. In said drawings, which show, for illustrative purposes only,preferred forms of the invention:

FIG. 1 is an enlarged view in perspective, showing an intraocular lensand unitary mount of the invention, ready for operative implantation, asin the course of a cataract operation;

FIGS. 2 and 3 are plan views of the unitary mount of FIG. 1, FIG. 2being to show an interim formative condition, and FIG. 3 showing thefully formed mount ready for assembly to the lens element;

FIGS. 4, 5 and 6 are fragmentary sectional views taken at the planes 4,5 and 6 indicated in FIGS. 1 and 3;

FIG. 7 is a view similar to FIG. 3 to show a modification;

FIG. 8 is an enlarged fragmentary view of the structure of FIG. 7, topermit identification of dimensional features;

FIG. 9 is a fragmentary sectional view, with solid outlines as taken atthe plane 9, and with phantom outlines as taken at the plane 9' of FIG.7;

FIG. 10 is a view similar to FIG. 9 to show a modification;

FIGS. 11 and 12 are perspective views to show further modifications;

FIGS. 13 and 14 are plan and perspective views to show the blank formand the ultimately bent configuration of a mounting that is particularlyadapted to manufacture from a plastic material;

FIG. 14A is a fragmentary view similar to FIG. 14, to show a variation;

FIG. 15 is a fragmentary plan view of a photographically duplicatedplurality of lens-mount blanks, in side-by-side severably connectedmultiple; and

FIGS. 16 and 17 are plan and fragmentary plan views similar to FIGS. 14and 15, to illustrate another application of the method of theinvention.

Referring to FIGS. 1 to 6, the invention is shown in application to animplant lens 10 of non-toxic transparent plastic, such asmethylmethylacrylate. Lens 10 is of such refractive index and is soground that when mounted at the iris and immersed in the intra-ocular,the thus-implanted eye will develop sharp image focus at the retina.Lens 10 is typically although not necessarily circular about its opticalaxis; it may, for example, be of 5-mm diameter and have aperipheral-edge thickness T of 1-mm or less.

In accordance with the invention, unitary mounting structure 11 issecured to lens 10 and provides first and second pluralities of radiallyoutward feet for axially stabilized positioning reference to the iris,the feet of one plurality being axially offset from and angularlyinterlaced with those of the other plurality, so that both sides of theiris contribute to stability. As shown, a circumferentially continuousring 12 conforms to the peripheral contour of the edge of lens 10, beingpositioned adjacent one face of the lens. The first plurality of feetcomprises three angularly spaced rods 13 extending radially outward forretention adjacent the outer side (anterior surface) of the iris, withthe pupilary border of the iris itself closing upon the circular edge ofthe lens. The second plurality of feet comprises three radially outwardloops 14 in a radial plane which is axially offset from ring 12, tosubstantially the extent T. Thus, each of the feet 14 includes twospaced short offset leg portions 15 which engage the circular edge oflens 10, and the radial loop portion extends from the leg portions 15.For the case of the plastic lens 10 of FIG. 1, six L-shaped anchoringprongs 16-17 extend first radially inwardly and then axially rearwardly,the same being embedded into adjacent rim regions of the lens 10.

The described mounting structure or adapter 11 may be a single piece ofmetal, with all anchoring prongs 16-17 and stabilizing feet 13-14integrally formed with the body ring 12. The metal is inert to bodytissue and fluids and is suitably stainless steel, of thickness in theorder of 0.1-mm. I have found it practical to construct the "blank" ofFIG. 2, for the mounting structure 11, by employing photographic andetching techniques.

More specifically, for the case of the "blank" of FIG. 2, a drawing wasinitially prepared, to greatly enlarged scale, e.g., 40 times. Thisdrawing was photographically reduced to ultimate size, and multiplied atindexed locations to produce a photographic negative with plural reducedimages of the drawing. Then, one of a class of metals which wastolerated by the body (e.g., stainless steel, platinum, irridium, etc.)was coated with a photosensitive material. The negative was placed incontact with the photosensitive coat, exposed to light, and thendeveloped in a "photographic reversal", thus removing from the exposedsurface those areas which have been exposed to light. The sheet that wasleft was then placed in a chemical solution (ferric chloride) whichetched away unwanted material, leaving only a completed profile of the"blank". The described etching process has the advantage that it tendsto produce round, burr-free edges, and it can use materials that arelighter and thinner than anything which to my knowledge and belief hasbeen available to date.

FIG. 2 depicts the "blank" thus prepared, it being noted that lobes 14'are of extended radial projection, in order to account both for theoffsets 15 and the loops 14; by the same token, the barbs 16'-17' are ofextended inward radial projection, in order to account for both theradially inward and the axially inward leg portions of prongs 16-17.Bending dies are employed to operate upon the "blank" of FIG. 2, suchthat all necessary axial offsets are produced, resulting in reduction ofthe overall circle defined by legs 14 and expansion of the circledefined by prongs 16-17, all as appears from comparison of the "before"and "after" plan views of FIGS. 2 and 3.

To complete the description of an actual physical embodiment of FIGS. 1to 6, I indicate that each of the retaining rod-like feet 13 terminateswith a small knob formation, to avoid presentation of any sharp edge toirritate iris tissue. These knobs are on a circle of 7.5-mm diameter,and the outer limits of legs 14 are on a circle of 8-mm diameter. Theprongs 16-17 are bent axially at a location radially inwardly offsetabout 0.15-mm from the body ring 12; they are embedded into lens 10 tothe extent of about 0.30-mm in the axial direction. Such embedding maybe accomplished without drilling, by axially directed ultrasonic drivingimpulses applied at prongs 16-17, while retaining ring (12) and leg(13-14) parts of the adapter 11 in damped condition. The opticaldistortion of lens 10 due to such driven assembly of the adapter to thelens is negligible.

In the embodiment of FIGS. 7 to 9, the layout of the adapter "blank" isgenerally as described for FIG. 2, with the exception that the radius R₁of the body ring 12' exceeds the radius R₂ of the lens 10' about itsoptical axis to an extent ΔR which is slightly less than the effectiveradially inwardly projecting extent ΔR' of the anchoring barbs 16'-17'.The interlaced pluralities of radially outward stabilizing feet 13'-14'are in axially offset relation, each plurality being offset in thedirection opposite the other plurality, as is apparent from FIG. 9. Toassemble the adapter of FIG. 7 to its lens 10', the body ring 12' istransiently distorted by suitable tooling, in approach to a polygonalshape; the action of such tooling is denoted by radially inward andradially outward arrows which symbolize local force application totransiently radially outwardly displace all barbs 16'-17' to clear theouter-edge on rim radius R₂ of lens 10'. Once axially centered aroundthis rim, the tooling is relaxed to allow compliant restoration, barbs16'-17' contact the lens rim and are then driven into short radial localembedment in the lens, as by ultrasonic tool means. The assembly is thencomplete and ready for sterilization and implantation.

FIG. 10 illustrates a slight modification of FIGS. 7 to 9, wherein thering body 12" is at one axial end of lens 10" and the pluralities ofstabilizing feet 13"-14" determine iris retention in a plane that isaxially offset from lens 10". The barbs 16"-17" are longer thanpreviously described, to permit an axially offsetting projection fromring 12" before radially inward bending to engage and become locallyradially embedded at spaced locations along the rim of lens 10".

In the embodiment of FIG. 11, the rim of lens 20 has a peripheral groove21, and the unitary mounting adapter 22 is so formed as to permanentlyassemble by resilient snap action into the groove 21. Adapter 22 maystill be formed from a single piece "blank" by the indicatedphoto-chemical technique, and it may still be a circumferentiallycontinuous structure. As shown, the looped legs 23 comprising oneplurality of locating feet integrally connect adjacent ends of spacedbody-ring arcs 24, and the rod-like feet 25 of the other pluralityextend radially from the respective arcs 24; axial offset of thesepluralities is built into legs 23, in the manner generally as describedat 15 in FIG. 1, except for a small initial radially outward offset insuch legs 23 at juncture with arcs 24. In unstressed condition, the arcs24 are of curvature conforming to that of groove 21 and are preferablyat a slight radially inwardly displaced position with respect to thecircle of groove 21. To assemble to lens 20, arcs 24 are outwardlyspread against the compliant action of loops 23, in order to permitplacement and resilient snap retention of arcs 24 in groove 21. Theassembly is then ready for sterilization and implantation.

In the embodiment of FIG. 12, the circular body ring 30 of a unitaryadapter 31 is retained in its assembly to a lens 32 by radially inwardbarbs 33-34 of one plurality (33) which engage over one axial end oflens 32 and of another plurality (34) interlaced with the barbs of thefirst plurality and engaging over the other axial end of lens 32, thusretaining the assembly without resort to mechanical embedment in lensmaterial.

As shown, the iris-stabilizing feet 35 of one plurality are spacedradial rods at the ring locations of barbs 34, and barbs 34 includeaxial offsets to the extent of lens-rim thickness. The feet 36 of theother plurality include axial offsets at juncture to the body ring 30,at which locations barbs 33 also extend radially inward. Feet 36 differfrom the loops already described in that they are somewhat coiled orlooped in a common radial plane, the free end of the coil beingapertured at 37. FIG. 12 will be understood to depict the unstressednormal condition and orientation of feet 36.

In accordance with a feature of the invention, the inherent resilientcompliance of feet 36 and their apertured ends 37 are employed tofacilitate operative insertion through the pupil of the iris. Inpreparation, a suture 38 such as a filament of nylon is tied with a loop38' intermediate its free ends 39--39'. The end 39 is threaded throughall foot apertures 37 before passing through loop 38' and is thentightened, to radially inwardly compliantly draw all foot ends 37 towithin the peripheral confines of lens 30, as denoted by phantomoutlines 36' in FIG. 12. In operative insertion of the retracted legs 36past the pupil, the suture ends 39--39' are held back, the end 39 beingtightly held until release when legs 36 are safely behind the iris. Uponrelease of the end 39, the other end 39' is drawn, thereby firstwithdrawing the loop 38' and allowing the remaining end 39 to pull outof loop 38' and all apertures 37 before complete removal of the suture.

FIGS. 13 and 14 depict another lens-mount embodiment of the inventionwherein the ring-like body comprises plural spaced arcuate spans40-41-42 between integrally connected loops 43, and wherein at each loopa short bridge 44 (at a radial offset Δr, with respect to the circle ofbody arcs 40-41-42, in the blank of FIG. 13) connects the spaced legs ofthe loop and circumferentially strengthens the circumferential integrityof the body. Radially inwardly extending from each bridge 44 is alens-retaining formation 45, effectively isolated from the associatedbridge 44 except for arcuately spaced integral leg connections 46thereto. The rod-like feet 47 of previously described embodimentsradiate centrally from each of the body arcs 40-41-42.

The blank of FIG. 13 is bent by suitable tooling into the lens-retainingconfiguration shown in FIG. 14, wherein it is seen that the projections45 have been axially offset from the plane of body arcs 40-41-42, sothat the respective axial limits of the periphery of the lens element(suggested by phantom outline 48) are engaged to permanently retain thelens to its mount. The relatively substantial radial extent Δr' by whichbridge 44 is connected to the legs of each loop 43, in the context ofthe relatively torsionally compliant nature of connection of each loop43 to its adjacent body arc (40-41-42) will be understood to enabletransient radially outward manipulation of any of the lens-engagingprojections 45 merely by axially deflecting one of the loops 43, thusreadily permitting insertion of and engagement to a lens 48 at its rim.

To complete the description of FIG. 14, the loops 43 will be seen alsoto have been subjected to bending, such that each bridge element 44extends axially to provide an axial offset for the radial plane of loops43 with respect to the radial plane of feet 47, so that loops 43 andfeet 47 may engage opposite sides of a supporting iris.

Also shown in FIGS. 13 and 14 is the provision of a singularly widebody-arc element at 42, for identification purposes, e.g.,manufacturer's mark, lens-identifying code, and date of manufacture.

Thus far, the invention has been described in the particular context ofusing a metal as the material of the lens-mounting structure. This isnot to be taken as precluding the use of other materials, as for examplea suitably inert plastic, such as nylon or polypropylene. In a preferredemployment of a film sheet of nylon or a high-temperature polyimide(e.g., Kapton, a product of E. I. DuPont Company), very much the sameetching technique may be employed as above indicated for the case of anetched sheet of metal. This close similarity will appear from thefollowing Example I, being a specific recital of steps to produce theplastic article.

EXAMPLE I

1. A sheet of nylon or polyimide film is selected, 0.002 to 0.005-inchthick, being the same thickness range as used in the etched-metaltechnique described above. The selected plastic sheet is tested forwater content, mechanical strength, and spectrographically for fidelityof composition.

2. The sheet is washed in acetone and is then air-dried.

3. The sheet is washed in distilled water and is then air-dried.

4. The sheet is visually inspected for cleanliness and surface defects.

5. The sheet is prepared for a photo-resist coating by vacuum or otherdeposition of chromium.

6. A photo-resist coating of photographic emulsion is applied to bothsides of the sheet and is then allowed to airdry.

7. By first preparing a drawing at 20× to 50× scale, and thenphotographically reducing it, in steps as necessary, culminating inreproduction onto a glass photographic plate, a master negative is madeto ultimately desired scale; preferably, the master negative includes aplurality of duplicates of the same photographically reduced drawing, inside-by-side adjacency and with interconnected leg formations, as willappear for the tangential rod-like connections 50 to legs of theconfiguration repeated in FIG. 15.

8. The nylon or polyimide film sheet is placed in a vacuum frame toflatten and hold it tight against a glass platten, and the masternegative is photographically exposed to both sides of the sheet, withaccurate registry.

9. The exposed sheet is developed, with the result that areas are notdeveloped where masked by the negative and, therefore, not exposed tolight. The areas reached by light are washed away by the developer, andin the case of a polyimide sheet, there may be an initial etching actionattributable to the developer.

10. The developed sheet is fixed.

11. The sheet is etched, hydrazine hydride being used for the etching ofnylon or polyimide sheet, and being usable for certain other plasticmaterials.

12. The photo-resist is washed away, using either a plasma process or afluorocarbon cleaner.

13. The resulting lens-mount sheet of severably connected part blanks isthen dipped in a 30 percent solution of hydrazine hydride, to round-offedges of the parts.

14. The sheet of otherwise-finished parts is degassed, by increasingsheet temperature to 300° F. in the case of nylon, or 500° F. for thecase of high-temperature polyimide.

15. The mounting rings are cut free from the sheet, at 50, to createindividual ring blank parts, as in FIG. 13.

16. Individual ring parts are mechanically bent to profile, as appearsin FIG. 14, and the profile is inspected.

17. A glass or molded-plastic lens is selected and mounted, as appearsfrom the phantom-outline relation in FIG. 14.

18. The total assembly is inspected, and the assembly is marked, withserial number and code, at 42 in FIG. 14.

19. Final inspection is performed.

20. The total individual assembly is plasma-cleaned and packaged, andthen gas or autoclave-sterilized.

21. Final inspection is performed through the package window, and thepackage is marked, as to date and lot.

A totally different photo-etch or other erosion technique is alsoapplicable to manufacture of lens-mounting adapters of the presentcharacter, particularly for the case of such adapters formed fromplastic sheet, as will appear from the following Example II.

EXAMPLE II

1. Two matching metal masks or master sheets, for example of aluminum,are prepared as in accordance with the photo-etch technique described atpage 5 above.

2. A sheet of suitable plastic, such as nylon or polyimide film, isselected, 0.002 to 0.005-inch thick, and is subjected to tests, washingand drying as noted at steps 1 to 4 of Example I.

3. The metal master sheets are cement-laminated to the front and backsurfaces of the plastic sheet, in precise register.

4. The plastic-sheet laminate, thus masked, is exposed to the dischargeof a plasma generator or micro-ion mill, in the presence of a suitablereactive gas, for example for one hour, until the desired configurationhas been generated by erosion of unmasked regions of the plasticmaterial.

5. The cement is dissolved to permit removal of the aluminum masks ormaster sheets for cleaning and re-use.

6. The configurated plastic sheet has the appearance of FIG. 15 and maybe cleaned by further exposure as in Step No. 4 of this Example II, forexample for an exposure time of approximately two minutes, to remove anypossible organic debris and burrs.

It will be seen that I have described intra-ocular lens and mountstructures meeting all stated objects, and, importantly, lendingthemselves to mass-production techniques, of inherent precision andcontrol. The drilling operations previously considered necessary havebeen totally avoided, as has also the reliance upon multiple parts, thussimplifying manufacturing and avoiding generation of waste particles.While plastic lenses have been specifically mentioned in severalillustrative contents, it will be appreciated that the invention is notnecessarily limited to such use. For example, glass lenses are to bepreferred and certainly can be well and safely mounted, using structuresof FIGS. 11 to 14. Also, although circular lens body-ring peripheralcontours have been described for all forms, it will be appreciated thatthis was purely to simplify description, in that the describedtechniques and structures have equal application whatever the peripheralcontour of the lens; for example, an oval lens-rim contour may beselected for more ready operative insertion past the pupil, for certainpatient requirements, and to reduce the chance of surgical trauma. Stillfurther, the inherent nature of the mounted lenses of the invention issuch that an absolute minimum of structure ever protrudes into theanterior chamber of the eye; thus, danger of corneal-tissue contact withany part of the intra-ocular lens structure of the invention issubstantially less than that with prior art structures. For thedisclosed forms of the invention wherein the iris closes on a circularlens periphery, there is minimal stress on the sphincter muscle, withattendant reduced risk of trauma.

In the discussion thus far, it has been indicated that the lens elementaccommodated by my mounting-ring adapter may be of glass or plasticmaterial, the implication being that the lens element is a separatearticle of manufacture, later assembled to its mount. However, it willbe appreciated that every one of the described mounting-ring embodimentsis applicable to placement in a suitably formed lens-molding cavity suchthat at least the lens-retaining part of the mounting ring is embeddedin a plastic lens element that is injection-molded in the cavity. Theblank of FIG. 13 lends itself particularly well to such use at the timeof injectionmolding the lens element, in that the lens-retainingextension 45 need not be bent radially, as shown in FIG. 14, but rathermay merely be bent axially, as shown at 45' in FIG. 14A, in which caseinjection-molding lens material may be forced in the molding process toenter the slot or opening 49 between bridge 44 and extension 45.Thus-molded, the lens element will be positively keyed and located byradially outwardly formed lens material at each of the openings 49.

It has also been indicated above that the preferred process of etchingdeveloped regions of a photographically reduced lens-mount masternegative lends itself to quantity production of pluralities of such lensmounts, in adjacent multiple as suggested in FIG. 15. And suchproduction lends itself to further options in regard to assembly withplastic lens elements. In one procedure, the individual mounting blanksare severed at 50 and are then bent to form lens-retaining projections,as described at 45' in connection with FIG. 14A; the individual mount,thus-prepared, may then be assembled to the lens-molding cavity forlocalized embedding in the lens material in the course ofinjectionmolding the lens. Alternatively, the lens-retaining projections45' may be bent out of all lens-mount structures in a large plurality ona single sheet, prior to severance at 50; in that event, and with thesheet of thus-formed lens mounts suitably introduced to amultiple-cavity mold for simultaneously molding a similarly spacedplurality of lens elements, all of the plural lens-and-mount assembliesmay be completed in a single injection-molding step, i.e., a singleinjection-molding of all lens elements, each into assembled relationwith its own mount. Thus formed, the plural assemblies are convenientlyhandled, shipped and stored as a single sheet, with severance ofindividual assemblies at 50, only when and as needed.

While the invention has been described in detail for the preferred formsshown, it will be understood that modifications may be made within thescope of the invention. For example, the reference to metal for theadapter structures of FIGS. 11 and 12 will be understood to beillustrative, since similarly formed and suitably stiff and non-toxicplastics may also serve the same purpose. Also, the reference tophoto-chemical preparation of metal "blanks" is illustrative of apreferred technique, in that photo-resist and plating techniques of theprinted-circuit technology, with subsequent release from a substrate,may also be employed; and the use of positive and negative terminologyin reference to photographic processing will be understood to beillustrative and not limiting, in that reversal development techniquesfor proceeding from positive original, directly to a positive-developedimage, are also to be understood as applicable.

Also, while metal-ring structures have been disclosed in combinationwith the lens element thereby mounted, it will be understood that suchunitary structures may be, and in certain cases preferably are,subjected to an inert protective coating of a plastic material such asnylon, thus assuring against any possibility of a minute metal burr orbarb projecting for body-tissue contact. By the same token, thedescribed plastic-sheet embodiments and methods will be understood torelate to basic structural formations and not necessarily to beconcerned with such final coating or finishing as may be desired forparticular purposes; for example, a coating of inert material, such asvacuum-deposited or sputtered Telfon or platinum may be applied to anotherwisefinished configurated adapter element, to provide enhancedassurance of a non-toxic ultimate product.

Still furher, it will be understood that although all mounting adaptersthus far described have been of single-piece unitary construction, thedescribed methods of manufacture are also applicable to multiple-piecemounting adapters, such as the two-piece configurations disclosed ingreater detail in my patent application Ser. No. 780,445, filed Mar. 23,1977, now U.S. Pat. No. 4,122,556. The basic blank element, i.e., forone half of such structure, is shown at 60, in solid outline in FIG. 16,with its two mounting lobes 61 projecting radially outward of itsring-like body 62, at diametrically opposed locations; another suchelement 63 is shown in phantom outline with its two mounting lobes 64 inangularly interlaced relation with lobes 61. The lobes (61) of oneadapter element (60) and the lobes (64) of the other adapter element(63) are retained in slotted interlobe regions 65-65' of the respectiveelements 60-63, and the thus-assembled adapter elements uniquely locateand retain a lens 66; when inserted in the eye, the lobes 61 stabilizethe assembly with reference to one side of the iris, and the lobes 64provide stability with reference to the other side of the iris. Thenature of the material of the elements 60-63 should be such that atleast the lobes to be inserted past the iris are resiliently (i.e.,flexibly) compliant, and highly satisfactory assemblies may be madewherein both adapter elements 60-63 are duplicates of each other, formedof suitable thin-sheet resiliently compliant plastic material, such asnylon or polyimide sheet, according to methods as described above atExample I and Example II. Thus a single multiple-element sheet, afragment of which is shown in FIG. 17, may be prepared to serve themounting-adapter element (60-63) purposes of a plurality of FIG. 16assemblies. It is to be understood, furthermore, that chemical etchingand mechanical, electronic or other erosion are to be deemed equivalentmanipulative steps, depending upon the manufacturing approach andselected materials involved.

What is claimed is:
 1. The method of making a self-supporting intra-ocular lens mount, which method comprises preparing to greatly enlarged scale a master plan view of the mount, said plan view being of a configuration defining a ring-like body with radially outward feet at angularly spaced locations and with lens-periphery engageable radially inward formations, selecting a thin flexible sheet of an etchable plastic material which is tolerated by the body and coating a surface thereof with photosensitive material, photographically exposing said photosensitive coating at reduced scale from said master plan view, developing the exposed coating to a positive image of the ring-like body upon the sheet, subjecting the developed side of the sheet to an etching chemical solution, and continuing the etching process until a substantially completed ring-like plastic blank results consistent with the positive image configuration.
 2. The method of claim 1, in which the coating step is performed on both sides of said sheet, and in which said reduced-scale photographic exposure is additionally made in reversed relation on the other side of said sheet with both exposures in geometrical register, both sides of the exposed sheet being developed and then etched.
 3. The method of claim 1, in which both exposures are made simultaneously on opposite sides of the sheet.
 4. The method of claim 1, in which the photographic-exposing step comprises exposure of said photosensitive coating to a plurality of adjacent duplicates of the photographic reduction of said drawing, whereby said development and etching steps produce a plurality of said ring-like plastic blanks.
 5. The method of claim 4, in which the plastic sheet material between adjacent duplicates of said photographic exposure is also exposed such that for each of said duplicates at least one of said feet has severable connection to adjacent plastic sheet material remaining between adjacent blanks.
 6. The method of making a self-supporting intra-ocular lens-mount element, which comprises preparing to greatly enlarged scale a drawing of a unitary flat blank for the element, said drawing being of configuration defining a ring-like body with radially outward feet at angularly spaced locations and with lens-engageable means extending radially inward of the lens periphery to be engaged thereby, selecting a thin flexible sheet of an erodable plastic material which is tolerated by the body, applying to a surface of said sheet an erosion-resistant mask which is a photographic reduction of said drawing to intended ultimate scale for the element, and subjecting the masked surface of said plastic sheet to an erosive environment until a substantially completed plastic blank results consistent with the mask configuration.
 7. The method of claim 6, in which a second and matching erosion-resistant mask is applied to the other surface of said sheet, in register with the application of the first-mentioned mask.
 8. The method of claim 6, in which the mask application involves photosensitive coating of the sheet, and photographic exposure and development of said photographic reduction.
 9. The method of claim 6, in which the mask application involves selection of a sheet of erosion-resistant mask material, photo-etched treatment of the mask-material sheet in accordance with said photographic reduction, thereby producing a mask that is separate from the sheet of erodable plastic material, and retention of the mask to a surface of the erodable plastic sheet during exposure to the erosive environment.
 10. The method of claim 6, in which the step of subjecting to an erosive environment includes chemical etching.
 11. The method of claim 6, in which the step of subjecting to an erosive environment includes exposure to the discharge of a plasma generator.
 12. The method of claim 6, in which the step of subjecting to an erosive environment includes exposure in a micro-ion mill in the presence of a suitable reactive gas.
 13. The method of claim 6, in which said mask contains a plurality of adjacent duplicates of the photographic reduction of said drawing.
 14. The method of claim 13, in which the mask includes mask material between adjacent duplicate photographic reductions of said drawing such that for each of said duplicates at least one of said feet has severable connection to adjacent mask material, whereby after the erosion step erodable plastic material remains to severably retain a plurality of duplicate plastic lens-mount elements in readiness for use when and as needed.
 15. The method of claim 1 or claim 6, in which said plastic sheet material is a nylon film.
 16. The method of claim 1 or claim 6, in which said plastic sheet material is a polyimide film.
 17. The method of claim 11 or claim 12, in which said erosion-resistant mask is of aluminum sheet material.
 18. The method of claim 17, in which said mask is one of two, laminated to the front and back surfaces of the plastic sheet in precise register, prior to erosive-environment exposure. 